Sciencemadness Discussion Board

Recycling broken mirror

nelsonB - 7-9-2013 at 23:49

Hi
i was looking at how mirror is made
knowing there silver in them i was wondering if we could recycle mirror for its silver content since silver have a value

bfesser - 8-9-2013 at 05:46

Yes, you can. Dissolve the silver with nitric acid to recover silver nitrate. Many mirrors will have a protective varnish or even paint over the silver, however. Don't expect high yields.

However...

InertGas - 8-9-2013 at 13:42

Quote:
...by the 19th century mirrors were commonly made through a process by which silver was coated onto a glass surface. Today, sputtering aluminium or other compounds are more often used for this purpose, although the process may either maintain the name "silvering" or be referred to as aluminising...
Wikipedia - "Silvering"

cyanureeves - 8-9-2013 at 17:22

i think the silvered mirrors are the old ones that develop greenish black spots.

phlogiston - 9-9-2013 at 11:34

Yes, I think so too. Also, it appears to me that there is a subtle but perceptible difference in color between the antique silver mirrors, (or at least the ones I have) and the modern ones, the antique ones being slightly more yellow in color ('warmer'). Ofcourse, this may very well be due to differences in the color of the old glass rather than the metallic coating.

Varmint - 10-9-2013 at 02:50

I would imagine its been several decades (at a minimum) since silver was used for volume production of mirrors.

Besides, the amount actually desposited would be miniscule, and unless reagents were recycled in a cost effective manner, I can almost guarantee you will have consumed more in reagent cost than the silver is worth.

DAS

Fantasma4500 - 10-9-2013 at 10:24

damnit.. i thought it was all mirrors that was made with silver?
anyhow, i suggest you first make it into small particles then proceed to ballmill it and not inhale any powder vapours if there is any, and let it settle, as glass ofcourse isnt a good thing to inhale
perhaps if you have alot you might want to consider adding the fine powder to water and then stirring it together
the silver should settle much faster than the glass, due to the massive density difference
the reason for this step would be that you would need alot of HNO3 to cover the whole powder, which will mostly be SiO2
if youre looking for silver, with pliers pick off the little squares with some grey metal found on motherboards, remaining after the silver has been made into silver nitrate should be palladium and probably some ceramics, so dont throw that away